Calendar.OnVisibleMonthChanged Method (DateTime, DateTime)

 

Raises the VisibleMonthChanged event of the Calendar control and allows you to provide a custom handler for the VisibleMonthChanged event.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

Protected Overridable Sub OnVisibleMonthChanged (
	newDate As Date,
	previousDate As Date
)

Parameters

newDate
Type: System.DateTime

A System.DateTime that represents the month currently displayed in the Calendar.

previousDate
Type: System.DateTime

A System.DateTime that represents the previous month displayed by the Calendar.

The VisibleMonthChanged event is raised when the user clicks the next or previous month navigation elements on the title section.

Raising an event invokes the event handler through a delegate. For more information, see NIB: Events and Delegates.

The OnVisibleMonthChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors:

When overriding OnVisibleMonthChanged in a derived class, be sure to call the base class's OnVisibleMonthChanged method so that registered delegates receive the event.

The following code example demonstrates how to specify and code a handler for the VisibleMonthChanged event to display whether the Calendar has moved forward or backward one month.

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">
    <title> Calendar VisibleMonthChanged Example </title>
<script runat="server">

      Sub MonthChange(sender As Object, e As MonthChangedEventArgs) 

         If e.NewDate.Month > e.PreviousDate.Month Then

            Message.Text = "You moved forward one month."

         Else

            Message.Text = "You moved backwards one month."

         End If

      End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> Calendar VisibleMonthChanged Example </h3>

      Select a different month on the calendar. 
      <br /><br />

      <asp:Calendar id="Calendar1" runat="server"
           OnVisibleMonthChanged="MonthChange">

         <WeekendDayStyle BackColor="gray">
         </WeekendDayStyle>

      </asp:Calendar>

      <hr /> 

      <table border="1">

         <tr style="background-color:Silver">

            <th>

               Month navigation direction

            </th>
         </tr>

         <tr>

            <td>

               <asp:Label id="Message" 
                    Text="Starting Month." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">
    <title> Calendar VisibleMonthChanged Example </title>
<script runat="server">

      Sub MonthChange(sender As Object, e As MonthChangedEventArgs) 

         If e.NewDate.Month > e.PreviousDate.Month Then

            Message.Text = "You moved forward one month."

         Else

            Message.Text = "You moved backwards one month."

         End If

      End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> Calendar VisibleMonthChanged Example </h3>

      Select a different month on the calendar. 
      <br /><br />

      <asp:Calendar id="Calendar1" runat="server"
           OnVisibleMonthChanged="MonthChange">

         <WeekendDayStyle BackColor="gray">
         </WeekendDayStyle>

      </asp:Calendar>

      <hr /> 

      <table border="1">

         <tr style="background-color:Silver">

            <th>

               Month navigation direction

            </th>
         </tr>

         <tr>

            <td>

               <asp:Label id="Message" 
                    Text="Starting Month." 
                    runat="server"/>

            </td>

         </tr>

      </table>

   </form>

</body>

</html>

.NET Framework
Available since 1.1
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